The US Food and Drug Administration has approved Utebzi (tebipenem pivoxil), an oral antibiotic developed by GSK plc (NYSE: GSK) and Spero Therapeutics (Nasdaq: SPRO), for the treatment of complicated urinary tract infections (cUTIs) including pyelonephritis in adult patients with limited or no alternative oral treatment options.

According to a press release from the companies, Utebzi is the first oral carbapenem antibiotic approved in the US. Carbapenems have previously been available only through intravenous administration. The drug is indicated for infections caused by specific susceptible pathogens, including Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis.

The approval is based on results from the PIVOT-PO phase III trial, which evaluated oral tebipenem pivoxil against intravenous imipenem-cilastatin in hospitalized adults with cUTI. Tebipenem pivoxil achieved a 58.5% overall success rate (261 of 446 participants) compared to 60.2% (291 of 483 participants) for imipenem-cilastatin, meeting the non-inferiority threshold. The most frequently reported adverse events, occurring in at least 3% of patients, were diarrhea and headache, described as mild or moderate and non-serious.

More than 3 million cUTI cases are treated annually in the US, with treatment failure affecting up to 34% of patients. These infections account for over $6 billion per year in healthcare costs.

The drug carries contraindications for patients with hypersensitivity to beta-lactam drugs and those with carnitine deficiency. Warnings include risks of hypersensitivity reactions, seizures, and interactions with valproic acid.

The development was supported in part by funding from the US Department of Health and Human Services through the Biomedical Advanced Research and Development Authority. GSK entered into an exclusive global licensing agreement with Spero Therapeutics in September 2022, covering all markets except certain Asian territories.

Utebzi is anticipated to be made available to US patients by the end of 2026.